<html>
    <head>
        <meta charset="utf-8">
        <title>啦啦</title>
        <style>
            div {
                width: 40px;
                height: 40px;
                float: left;
            }
        </style>
    </head>

    <body style="width: 80px;">
        <div style="background-color: red"></div>
        <div style="background-color: blue"></div>
        <div style="background-color: yellow"></div>
        <div style="background-color: green"></div>
    
        <script src="click.js"></script>
    </body>
</html>